Eevee emission reflections disappear when out of view
You seem to be mistaking your bloom effect with indirect lighting.


Left: Indirect lighting, Right: Bloom

Bloom will not be visible once an object disappears from view (e.g. when the camera angle changes). The indirect lighting is very faint in your example since the emissive area is very small and the illumated surfaces are at a 90° angle.

However, even increasing the brightness of the emissive material won't help much if the samples of the light probe are too few. You will quickly get unnatural artefacts.



A solution could be to use a very dense light probe and a very bright emissive light. You will have to reduce/adjust the bloom effect which will be even brighter then.


Many samples.

But as you can see, there are some artefacts. Light probes are not very useful for very small emissive lightemitting meshes. A real solution would be, to reproduce the emission with normal lamps.